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Date November 2014 Marks available 1 Reference code 14N.1.HL.TZ0.21
Level Higher level Paper Paper 1 Time zone TZ0
Command term Question number 21 Adapted from N/A

Question

On sites polluted with heavy metals, some grasses show tolerance to concentrations of those metals that are normally toxic. What explains this tolerance?
A. Grasses continually exposed to high doses of heavy metals mutate.
B. Rapid reproduction rate of grasses produces little genetic variation.
C. Grasses not killed by the heavy metals reproduce and pass on their genes.
D. Heavy metals become less toxic over time.

Markscheme

C

Examiners report

[N/A]

Syllabus sections

Additional higher level » Topic 8: Metabolism, cell respiration and photosynthesis » 8.2 Cell respiration
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